Last year, the amount workers or employers could set aside pre-tax for commuting on public transit dropped from $230 to $125. But commuters who drove and parked weren't impacted. In fact, the cap for parking costs increased from $230 to $240.

The fiscal cliff deal re-establishes "parity" on this break for public transit users. They can now sock away $240 a month for 2013.

Still, the legislation made this change retroactive to 2012. It's Only Money's isn't sure what that means, practically speaking. Do commuters who could have socked more away each month last year suddenly get to make up for that? If so, how? On their 2012 Form 1040?

We'll see.

Do you have any questions on how the fiscal cliff deal impacts your taxes? Send 'em It's Only Money's way, either in the comments below or by e-mail. Check back on the blog for more details.